After pleading guilty to second-degree murder and armed criminal action, the now-18-year-old Bustamante listened as the prosecution read entries from her diary at her sentencing hearing on Monday. Here's what Alyssa wrote on the night of the murder:

I just fucking killed someone. I strangled them and slit their throat and stabbed them now they're dead. I don't know how to feel atm. It was ahmazing. As soon as you get over the "ohmygawd I can't do this" feeling, it's pretty enjoyable. I'm kinda nervous and shaky though right now. Kay, I gotta go to church now…lol.

Apparently the church event was a youth dance for Mormons. The prosecution presented evidence that Alyssa hid a knife in her backpack, then used her little sister to lure 9-year-old Elizabeth Olten (pictured) out of her home. The teen killer told Elizabeth she had a "surprise" for her in nearby woods. The surprise was murder, followed by burial in a shallow grave.

Bustamante's lawyers argued for leniency, pointing out that the girl was born to teen drug addicts who abandoned her. (Her father went to jail; her mother turned over legal custody to Alyssa's grandparents.) She attempted suicide at 13; her doctor had increased her Prozac dose two weeks before the murder. The judge ultimately gave Alyssa the maximum sentence for her crimes, life in prison with the possibility of parole in 35 years. [AP, CBS, images via AP]